For cells that divide by mitosis there are three major parts of the cell cycle: interphase, mitosis, and cytokinesis. Review these major parts and answer the following questions so you are familiar with the major stages before beginning the laboratory.
Multicellular organisms grow by making more cells. A cell undergoing its cell cycle and mitosis results in two identical daughter cells. In plants special growth areas called meristems are typically found at the tips of roots and stems. In animals, growth is usually not relegated to a specific area of the organism.
For this lab we will be using prepared onion root tip slides to study plant mitosis and calculate the relative duration of the stages of mitosis. The cell cycle for actively dividing onion root tips is approximately 24 hours. Since these cells are not living, we will estimate the time each cell spends in each stage based on what percentage of the cells are in each phase.
Mitosis is divided into the following stages: prophase, metaphase, anaphase, and telophase. Match each stage with the major action taking place in the cell and then review the photos of onion root cells in Interphase and different stages of mitosis.
Match by drawing a line from the stage to the correct description of the cell activity:
|Interphase||Nuclear envelope reforms|
|Prophase of mitosis||DNA is duplicated|
|Metaphase of mitosis||Sister chromatid separate and move to opposite poles|
|Anaphase of mitosis||DNA condenses into visible chromosomes|
|Telophase of mitosis||Chromosomes align along the middle of the cell|